This invention relates to electrical circuits for firing explosives and, in particular, to a new and improved oscillator circuit for generating an electric spark between spaced electrodes for igniting a solid explosive, such as would be used in a firearm for propelling a projectile.
Battery-powered oscillator circuits have been utilized for producing electric arcs between electrodes for igniting a fluid fuel in a turbine engine, as shown in U.S. Pat. Nos. 3,671,805 and 3,731,144. Also, oscillator circuits have been utilized for energizing heating elements for setting off explosives, as shown in U.S. Pat. No. 4,141,297. However, it is an object of the present invention to provide a new and improved ignition circuit providing an electric spark between electrodes for igniting a solid explosive of the type used in firearms and the like.
The ignition circuit for a firearm should provide a hot, blue spark for igniting the solid explosive. Also, the ignition circuit should provide repeated firing capability with a minimum recovery time, so that the circuit can be used with automatic weapons. Another requirement is that the circuit have a minimum battery drain, so that the overall circuit including battery can be made quite small. These requirements are diverse in nature, and it is an object of the present invention to provide a new and improved ignition circuit having optimum performance characteristics.
It is a particular object of the invention to provide a new and improved ignition circuit which will produce the desired spark for the repeated firing of solid propellant explosives while operating with a small battery and having substantial operating life. A further object is to provide such a circuit which can be a solid state device without having any mechanical or moving parts other than the firing switch, and which can be made quite small, inexpensive, and reliable and of a configuration readily incorporated into a firearm.
A further object of the invention is to provide such an ignition circuit incorporating provisions for control of operating frequency and duty cycle along with current load so that the circuit can be modified for various end uses. Other objects, advantages, features, and results will more fully appear in the course of the following description.